UPDATE 9:25 AM: Pepperell High School has been reopened. The gas leak has been shut off and students and staff are being allowed to enter the campus.

A major gas leak has been discovered at Pepperell High School this morning. Police scanner traffic states a lawnmower struck an above-ground gas main, causing the significant leak, which officers say is between buildings on the campus.

Roads surrounding the high school are closed until the leak is corrected. That includes Van Tassel Drive, Dragon Drive and School Access Road.